--- ym2151.c.orig	2004-10-28 02:08:12.000000000 -0700
+++ ym2151.c	2004-10-30 02:13:25.551609448 -0700
@@ -2174,6 +2174,7 @@
 		if (op->pms)	/* only when phase modulation from LFO is enabled for this channel */
 		{
 			INT32 mod_ind = PSG->lfp;		/* -128..+127 (8bits signed) */
+			int steve = 0;
 			if (op->pms < 6)
 				mod_ind >>= (6 - op->pms);
 			else
@@ -2182,7 +2183,25 @@
 			if (mod_ind)
 			{
 				UINT32 kc_channel =	op->kc_i + mod_ind;
+				INT32 steve_channel =	op->kc_i + mod_ind;
+				if(steve_channel < 0) {
+					kc_channel = 0;
+					printf("steve_channel is %d, resetting kc_channel to zero\n",steve_channel);
+				}
+				printf("op kc_i is %x\n",op->kc_i);
+				printf("mod_ind is %x\n",mod_ind);
 				(op+0)->phase += ( (PSG->freq[ kc_channel + (op+0)->dt2 ] + (op+0)->dt1) * (op+0)->mul ) >> 1;
+				steve = (op+1)->phase;
+				printf("op+1 phase is %x\n",steve);
+				printf("kc_channel is %x\n",kc_channel);
+				steve = (op+1)->dt2;
+				printf("op+1 dt2 is %x\n",steve);
+				steve = (op+1)->dt1;
+				printf("op+1 dt1 is %x\n",steve);
+				steve = (op+1)->mul;
+				printf("op+1 mul is %x\n",steve);
+				steve = (PSG->freq[ kc_channel + (op+1)->dt2 ]);
+				printf("PSG freq is %x\n",steve);
 				(op+1)->phase += ( (PSG->freq[ kc_channel + (op+1)->dt2 ] + (op+1)->dt1) * (op+1)->mul ) >> 1;
 				(op+2)->phase += ( (PSG->freq[ kc_channel + (op+2)->dt2 ] + (op+2)->dt1) * (op+2)->mul ) >> 1;
 				(op+3)->phase += ( (PSG->freq[ kc_channel + (op+3)->dt2 ] + (op+3)->dt1) * (op+3)->mul ) >> 1;